RAYMONDVILLE — Immigrant rights groups Sunday stood in front of a 2,000-bed federal detention center here, calling on the government to “Shut down tent city.”

With cries like “No human is illegal,” about 75 demonstrators came from as far as San Antonio and Del Rio to protest the largest detention center in the United States.

When it opened last year, federal officials touted the futuristic compound as a centerpiece in the government’s crackdown on illegal immigration.

“Our main objective is to raise awareness of this tent city and to the separation of families,” said Elizabeth Garcia, a Brownsville activist who spearheaded the protest.

“These are families who bought a house with their savings. They bought a piece of land,” she said of detainees.

The demonstration marked the first protest of the $60 million detention center since its tent-like domes sprung up last summer.

“It’s important for us to realize that we’re condoning this in our own backyard,” Garcia said.

Over loud speakers, protesters called for an end to deportations at the detention center that holds illegal immigrants before they’re deported to their home countries.

“There’s a lot of people who have children who are American citizens,” said Juan Torres, an activist from Weslaco. “How can you say a child has committed a crime? Does that mean the father’s alleged crime transcends to his children?”

Jay Johnson Castro, who grabbed national headlines as he walked the border in protest of the planned border fence, called the detention center “a concentration camp.”

“This is the battle front of America right here,” he told reporters. “This is the largest concentration camp on Planet Earth.”

Others cited the detention center’s windowless design as inhumane.

“The whole idea of detention and incarceration is basically to kill the spirit of the human being, to send a message that if you don’t behave they’ll put you in a detention center,” said Rogelio Nuñez, executive director of Proyecto Libertad, an immigrant rights group in Harlingen.

Immigrant rights groups pointed to a U.S. inspector general’s report that found inhumane and unsafe conditions at five immigrant detention centers.

The probe — which did not include the Raymondville detention center — found inadequate health care, presence of vermin, limited access to clean underwear and undercooked poultry, a January report said.

While federal standards require that detainees have access to telephones and law offices, investigators found telephones missing or out of order, the report said.

But the Raymondville detention center didn’t have such problems, Marc J. Moore, field officer for Immigration and Customs Enforcement’s Detention and Removal Operation, told reporters in a March tour of the center.

Nina Pruneda, a spokeswoman for Immigration and Customs Enforcement in San Antonio, failed to respond to messages requesting comment Friday.